In an OK! Magazine exclusive, the article reports that the ceremoney was held outside in front of a "breathtaking" sunset at San Ysidro Ranch in Montecito, California and she walked down the aisle with her mother, Susan (dressed in Badgley Mischka), and her sister, Haylie, serving as maid of honor along with four other bridesmaids.
Hilary wore a "mermaid gown" by Vera Wang.
The issue of OK! Magazine featuring exclusive photos and inside information on the wedding and reception hit newstands this come Thursday.
"After having been together for over two years, they are very excited to share this happy news," her rep said. "They are thankful for all of your warm wishes."